Key Vikings return to practice Sunday

The few key players returned to practice for the Vikings on Sunday. Tight end John Carlson and defensive tackle Letroy Guion both returned from sprained knees, and defensive back Chris Cook returned from concussion symptoms.

After missing practice on Sunday, tight end Kyle Rudolph returned to the Vikings' practice field on Monday. He and Chris Cook were shaken up in Friday's preseason game against the Bills, and both were suffering from concussion-like symptoms. Cook remains out.

Litchfield Minnesota native John Carlson is doing everything he can to make sure he's able to play in the Vikings' season opener against the Jaguars on Sunday. Carlson missed most of training camp with a sprained knee, but head coach Leslie Frazier says the tight end mentally prepared to play in the game.

Two important starters sat out of Vikings practice on Sunday with concussion-like symptoms. Tight end Kyle Rudolph and defensive back Chris Cook were banged up in Friday's preseason win over the Bills, and while test results have been positive, the team won't risk any unnecessary contact.

Bad news for tight end John Carlson on Tuesday as he sprained his knee and could miss several weeks. Better news for Adrian Peterson as he returned to practice after an allergic reaction to some jambalaya he ate on Monday. And rookie left tackle Matt Kalil caused Jared Allen to curse loudly.

Redskins quarterback Robert Griffin III continues to improve after suffering a mild concussion on Sunday. He passed multiple tests on Tuesday and was cleared for practice. If he remains symptom free he'll play on Sunday.